Rack systems are provided for use in mounting or positioning of electronic components and other equipment. The disclosed rack systems that are seismically sound and adapted for packaging/shipment in a disassembled condition. The rack systems include at least one upright, a base assembly and a top frame assembly. The base assembly includes a base unit, at least one internal upright brace and at least one external upright brace. The base assembly defines a bounded region for receipt of an upright. Similarly, the top frame assembly defines a bounded region for receipt of the opposite end of the upright. When assembled at a desired location, the disclosed rack systems comply with applicable seismic-related design and performance parameters, including specifically the Zone 4 standard, and accommodate desirable cable management functions.